Log breaking device

ABSTRACT

A manually operated device for use in tree falling comprises an elongated manually operable lever having a first pressure plate at one end and a second pressure plate hinged to the first pressure plate. A pressure member is connected in spaced relation to the pressure plates by two links pivotally interconnected directly with the pressure member at one of their respective ends. The other ends of the links are connected to the pressure plates. Raising the lever causes the first pressure plate to pivot in relation to the second pressure plate and the links to raise the pressure member which bears against the tree sawcut, consequently felling the tree.

This invention relates to a manually operated log breaking device foruse in tree falling, and particularly to be used for the directedfelling of rooted trees.

It is an object of this invention to provide a log breaking device whichis lightweight, stable and structurally simple which can be effectivelyused with a minimum of wasted tree wood.

According to this invention there is provided a manually operatedmechanical log breaking device comprising an elongated manually operablelever having in the region of one end a first pressure plate, a secondpressure plate hinged to the first pressure plate and a pressure elementor elements connected in spaced relation to the first and secondpressure plates by two links pivotally interconnected with the pressureelement or elements at one of their respective ends, the other of therespective ends of the links being pivotally connected respectively tothe first and second pressure plates.

The first pressure plate preferably extends along the axis of the lever,which may have a handle at its other end.

The links and the pressure element are preferably mutually pivotallyinterconnected by engaging a common bolt or axle and a plurality ofparallel links may extend between the axle and the foot and the pressureplate.

One preferred pressure element is a third pressure plate pivotable aboutthe common axle, being substantially rectangular in shape and protrudingonly very slightly if at all above the surface of the first and secondpressure plates when the device is in the horizontal, insertion readyposition.

Preferred pressure elements include a plurality of cylindrical rollers,freely rotational about their central longitudinal axis on the commonaxle. Again, these rollers may only protrude slightly above the surfaceof the first and second pressure plates when same are level.

The rollers may be provided with teeth or other rough surface to helpincrease frictional grip with the tree fibre.

Preferably the pressure plates have projections from their outwardlypresented surfaces for similar purposes.

The active surface area of the roller incorporated device may beincreased by using same in conjunction with a separate pressure platewhich is pushed into engagement with the work by the rollers uponactuation of the device. In order that such plate will not fall off therollers the plate may be provided with a track or channel in thatsurface which engages the rollers in operation. Furthermore the lateralwidth of such channel corresponds approximately to the lateral distanceoccupied by the rollers and the links on their common axle.

Such modification of the plate eases the insertion operation of same,avoiding the necessity to hold same and simultaneously operate thedevice.

Alternatively or additionally such extra pressure plate may bemagnetized for greater adhesion to the rollers, eliminating the need tohold said plate in position.

A platform may be incorporated in the first pressure plate which servesto support or catch the underside of the pressure elements from suddenimpact encountered in wind felling.

The link or links pivotally connected to the first and second pressureplates from the common axle may be identical.

With a third pressure plate acting as the pressure element, the deviceis particularly useful in felling soft wooded or rotten trees. Thesurface area of such third plate is designed to support soft wood treeswithout damaging same under influence of the forces acting through thedevice.

Both embodiments of the device will operate within a smaller sawcut thanthe model disclosed in U.S. Pat. No. 4,030,700 with consequent reductionin wasted wood. The third pressure plate has a rounded chamfered leadingedge 4a. This is affected by reducing the thickness of the tool to beinserted in the sawcut.

The embodiment employing rollers is especially useful in fellinghardwood trees, the device taking advantage of the wedge shape cut inthe tree and being insertable further towards the felling hinge when thetree sways in the wind.

Springs and guiding members are eliminated from the structure which areprone to distortion or breakage. The tool structure is lightweight withfew moving parts which considerably reduces manufacturing costs.

The device according to this invention may be used effectively in awedge cut above the main horizontal sawcut, the device not needingmanual support until the felling is effected by levering on the handle.

Two embodiments of the invention will now be described by way of examplewith reference to the accompanying drawings in which:

FIG. 1 is a side elevation of the plate version extended.

FIG. 2 is a plan view of the plate version unextended.

FIG. 3 is a side elevation of FIG. 2.

FIG. 4 is a side elevation of the roller version unextended.

FIG. 5 is a side elevation of the roller and plate combinationunextended;

FIG. 6 is a perspective view of the multi roller version unextended; and

FIG. 7 is a side elevational view of a modification of the roller andplate combination of FIG. 5.

Referring firstly to FIGS. 1 to 3, a lever 1 is connected to a firstpressure plate or foot 2 which is hinged upon an axle 13 to a secondpressure plate 3. A first link 5 is pivotally hinged to the foot 2 by anaxle 9 and pivotally hinged to a third pressure plate 4 by an axle 7.This same axle 7 also pivotally engages a second link 6 to the thirdplate 4, the other end of the link 6 being pivotally hinged to thesecond pressure plate 3 by an axle 8. A platform 15 is provided betweenaxle 9 and axle 13 which serves to absorb impact on rebound to thepressure plate 4, relieving these said axles of stress in a tree swayingsituation.

The second pressure plate 3 has projections 10 for engaging with treefibre when the device is inserted into a sawcut. Insertion in a narrowcut is effected with the configuration of FIG. 3.

Raising the lever 1 causes the foot 2 to pivot in relation to the secondpressure plate 3 which remains gripping the tree fibre. The hinged links5, 6 cause the third pressure plate 4 to be displaced away from thesecond plate 3 until it engages the tree fibre on the complementary sideof the sawcut. Further levering on the handle 1 pushes the tree awayfrom the cut and is consequently felled.

In FIGS. 4 to 6 the pressure plate 4 is basically replaced by aplurality of cylindrical rollers 11 which has either teeth 12 or similarrough surface. The roller version is mainly useful on hard wood treessuch as pine, although by using same with an additional pressure plate14 (FIG. 5) soft wood or rotten trees may be successfully felled, theroller version alone being particularly suited to wind felling.

In the alternative embodiment illustrated in FIG. 7, the plate 14 ispivotally attached to the main axle 7 by two identical rings 20 atopposite ends of the axle 7, which rings 20 are fixedly attached to theplate 14 at opposite ends of the plate 14.

While particular embodiments have been chosen to illustrate theinvention, it will be understood by those skilled in this art thatvarious changes and modifications can be made therein without departingfrom the scope of the invention as defined in the appended claims.

What is claimed is:
 1. A manually operated mechanical log breakingdevice comprisinga longitudinally extending lever means; a firstpressure plate extending from one end portion of said lever means; asecond pressure plate pivotally coupled to said first pressure plate andhaving means on one surface thereof for engaging a saw cut in a log; atleast one pressure member having means for engaging a saw cut; and alink system interconnecting said pressure member and said first andsecond pressure plates with said pressure member spaced from said firstand second pressure plates, said link system comprisingan axle, and atleast two lever members, said pressure member and one end of each ofsaid lever members being pivotally coupled directly to said axle, theother end of each of said lever members being pivotally coupled to saidfirst and second pressure plates, respectively.
 2. A manually operatedmechanical log breaking device according to claim 1, wherein each ofsaid lever members includes a plurality of corresponding levers arrangedin parallel to each other.
 3. A manually operated log breaking deviceaccording to claim 1, wherein said pressure member comprises at leastone cylindrical roller rotatably mounted on said axle.
 4. A manuallyoperated log breaking device according to claim 3, wherein said rollershave a rough surface.
 5. A manually operated log breaking deviceaccording to claim 3, wherein said rollers have radially extendingteeth.
 6. A manually operated log breaking device according to claim 3,further including an additional pressure plate coupled to said rollers.7. A manually operated log breaking device according to claim 6, whereinsaid additional pressure plate has a channel in which said rollers arereceived.
 8. A manually operated log breaking device according to claim6, wherein said additional pressure plate is magnetized.
 9. A manuallyoperated log breaking device according to claim 1, wherein said pressuremember comprises a third pressure plate.
 10. A manually operated logbreaking device according to claim 9, wherein third pressure plate has asmooth, low friction surface and a rounded chamfered leading edge.
 11. Amanually operated log breaking device according to claim 1, whereinshock absorbing platform means are provided in said first pressureplate.
 12. A manually operated log breaking device according to claim 6,wherein said additional pressure plate is pivotally coupled to saidaxle.
 13. A manually operated log breaking device according to claim 1,wherein said means for engaging a saw cut comprise a plurality ofprojections.